Asymmetric Catalysis of Radical Addition

Entry Chiral ligand, Lewis acid Solvent Yield ee, %  

Reaction conditions Lewis acid (1 equiv), chiral ligand (1 equiv), 2-iodopropane (6 equiv), EtjB/ O2 (6 equiv), 25 C. 

Enantiomeric excess by HPLC (95 5 hexane 2-propanol, Chiralcel OD or AD). 

EtsN was added after the reaction to facilitate product isolation. 

Larger amounts (10 equiv) of 2-iodopropane and Et3B were used. 

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Asymmetric catalysis of radical addition to C=N bonds remains a challenge for further synthetic methodology development [48], Our effort toward this goal began with the hypothesis that the two point binding of Lewis adds by N acylhydrazones (Figure 2.6) would fadlitate the development of a versatile means of stereocontrol. 

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